1. Field of the Invention
The present invention relates to a novel optically active ester compound and a liquid crystal composition containing the same. More particularly, it relates to an optically active ester compound useful as a component of a ferroelectric liquid crystal composition and a ferroelectric liquid crystal composition containing the same.
2. Description of the Prior Art
Although the practical use of a liquid crystal element has started with the application thereof to the display of a watch or an electronic calculator, it is now applied to a widened field including pocket television, various displays and optoelectronic elements. Most of the liquid crystal display elements now used are of TN display type and use nematic liquid crystal materials. Since this type of display is of the photoreception type, it has disadvantages in that the speed of response is low and that the displayed images cannot be seen at some angles of vision, though it has advantages in that the eyes suffer little fatigue and that the power consumption is very low. In order to overcome these disadvantages, a display system using a ferroelectric liquid crystal has recently been proposed. Even in a display element using a ferroelectric liquid crystal, like in the case of the above TN liquid crystal display element, a ferroelectric liquid crystal must be practically used in a state mixed with several liquid crystal or non-liquid crystal compounds, i.e., as a so-called ferroelectric liquid crystal composition, in order to satisfy various characteristics.
On the basis of this idea, Japanese Patent Laid-Open No. 44548/1988 proposed the use of an optically active 2-methyl-1,3-propanediol compound as a component of a ferroelectric liquid crystal composition. However, a ferroelectric liquid crystal composition containing such a compound as a component is not sufficiently improved in the speed of response, though it is somewhat improved. Accordingly, a further improvement in the speed of response of a ferroelectric liquid crystal composition has been expected in order to put the composition to practical use.